Lens focusing and adjusting device



Jan. 3, 1950 1-. J. MORGAN EI'AL 2,493,463

. LENS FOCUSING AND ADJUSTING DEVICE 2 Sheets-Sheet 1 Filed Sept. 14, 1946 INVENTORS 24 fimnas' 1227p d'eozye P a ,cZ/

Jan. 3, 1950 1". MORGAN ETAL LENS FOCUSING AND ADJUSTING DEVICE Filed Sept. 14, 1946 2 Shets-Sheet 2 .9 &3

m5 07' a] a (52%??? Patented Jan..3, 1950 UNITED, sures PATENT OFFICE I 4 I 4 4 v LINSI'OCUSIZWEA ZD ADJUS J Hamish-Chi- Ampro Corporation,

amin Chicago, Ill, a corporation of Illinois Application September 14, 194. Serial No. 691,024 claims. (CI. 88-44) In motion picture projectors heretofore in common use, rough adjustment of the lens was accomplished by an axial movement and fine adjustment by a rotary movement of the lens relative to its mounting. In the production of projectors, inaccuracies in the construction of the lens barrel and mounting sometimes occur which cause an objectionable wobbling of the lens when ceptor and safety shutter which may be of the it is rotated to eifect the fine adjustment. When 7 the lens is rotated to accomplish the fine adjustment, it must turn in a true circle, otherwise, the wobbling of the lens will cause an objectionable vertical and lateral shifting of the projected image on the screen.

The main objects of this invention are to provide an improved lens focusing device in which both the rough and fine adjustments may be accomplished by an axial movement of the lens so as to avoid the objectionable shifting of the projected image caused by wobbling of the lens during rotation; to provide a lens mounting having an improved focusing sleeve which will permit a lens supported therein to be easily and quickly shifted for accomplishing the necessary rough and fine adjustments to focus the lens; to provide improved manually operable means for axially shifting the focusing sleeve; and to provide an improved lens mounting which may be easily and quickly assembled and which is particularly adapted for use in cinematographs.

An, illustrative embodiment of this invention is shown in the accompanying drawings. wherein:

Y 1 is a fragmentary side elevation of a cinematograph having an improved lens mounting.

Figure 2 is an enlarged vertical transverse section'of the lens mounting, the view being taken on the'line' 2--2 of Figure 1.

on the line Figure 4, the adjusting means being shown in elevation.

Figure-6 is a section taken on the line 6-4 of Figure 4.;

Figure"? is a perspective view of the shuttle which coacts with the cam of the adjusting means. Inasmuch as this invention relates particularly to the lens mounting, the accompanying drawings show only those portions of the projector which are located adjacent the lens mounting and a description of which will be of assistance in understanding the invention.

Cinematographs generallyinclude an upright casing having a rear compartment for housing construction shown in the application of Arthur S. Dearborn, Serial Number 690,699, filed August 15, 1946.

In the construction shown, the improved lens' mounting is applied to a cinematograph comprising a casing I on which is mounted the usual feed and take-up reels (not shown) for supporting a fllm 2 which is fed downwardly through a vertical guideway 3 by mechanism which includes a sprocket 4 and claw 5.

The improved lens mounting includes a bearin block 6 having a bore I in which is slidably mounted an axially shiftable focusing tube or shell 8 which supports a lens ferrule having a substantially circumferentially ribbed exterior, such as the usual externally threaded barrel or ferrule 9 of a lens ll.

The bearing block 6 is an integral part of a forwardly extending side wall ll of the casing I.

The outer smooth surface of the focusing tube I fits snugly within the bore 1 so as to prevent any wobbling of the tube when it is shifted axially to adjust the position of the lens for bringing the image into focus.

The inner surface of the tube 8 is smooth so as to permit a quick rough adjustment of the lens by a straight-line or rotary movement of the lens relative to the tube.

The improved means for manually shifting the focusing tube includes a stem 12 which is rotatably supported in a boss l3 on a cover plate M which is secured to the block 6 by screws It. A knob It is secured to the outer end of the stem l2 by a screw ll.

Formed on the inner end of the stem I 2 are a concentric guide washer l8 and an eccentric cam l9 coacting respectively with a pair of side flanges 20 and a pair of end flanges 2| formed on a shuttle 22 .which is slidably supported in a recess 23 formed in the bearing block 8. This shuttle serves as an operating connection be-.

in the focusing tube whereby mmovement of the shuttlewill be transmitted to the focusing tube and the lens which it supports. The extremity of the stud is rounded and extends into engagement with-the externally threaded ferrule l to adJustably secure the lens within the focusing;

tube.

The shuttle and its connected stud 21 are yieldably retained in operative position by a helical. spring 25 which embraces the stem it One end of the spring engages the cam ity and" ferrule, a cover dctachabiy securedto said sup-' fport, a stem rotatably mounted on said cover, a -knobonone endofsaid stem,acam ontheother end of said stem positioned in operative engagestud when the lens is shifted axially relative to said tube.

its other end abuts a shoulder 30 in the boss [3.

The inner face of the cam ll engages the edges of the flanges II, as shown in Fig. 5, so as to urge the shuttle and its stud 21 inwardly toward'th'e focusing tube. The stud I1 permits the lens I.

to be rotatedin the focusing tube and, by reason of its retractability, it permits the lens to. be

shifted axially in a straight-line movement relative to the focusing tube. v 1

This improved construction greatly facilitates the initial assembly of the projector. To} assemble the structure, the focusing tube 8 is inserted in the bearing block I andthe shuttle 22 is then placed in the recess 23 with the stud 27 extending through the aperture 28. The spring 29 is app ed to the stem i2 and the stem is then inserted in the boss I3, after which the knob i0 is secured to the outer end of the stem. The cover plate It is then applied to the bearing block so as to position the cam it in operative position between the flanges 2|. I

The lens I! is inserted'into the focusing tube and roughly adjusted by a straight-line movement which causes the shuttle 22, and stem i2 to be retracted against the'action of-the spring 2! whenevera thread of the ferrule 9 strikes the stud 21 To obtain a fine adjustment of the lens for focusing the image on the screen, the knob ll is turned so as to rotate the cam I! for moving the shuttle 22 which imparts an axial movement to the focusing tube and the lens.

Although but one specific embodiment of this invention has been herein shown and described,

it will be understood that details of the construction shown may be altered without departing from the spirit of the invention as defined by the following claims: a i

We claim:

1. In a device of the class described, the com-' bination with a lem having an externally threaded ferrule, of a mounting comprising a support, an axially movable focusing tube slidably mounted on said support for receiving the lens ferrule, a shuttle plate having a stud extending through an aperture in the wall of said tube for engagement with the threads of, the lens ferrule, a cover detachably secured to said support, a stem rotatably mounted on said cover, and a cam on said stem 'operatively engaging said shuttle plate for shifting said focusing tube axially upon the rotation of said stem.

2. In a .device of the class described, the J combination with a lens having an. externally threaded ferrule, of a mountingcomprising a support, an axially movable focusing tube slidably mounted on said. support for'receiving the lens ferrule, a shuttle plate having a stud extending through an aperture in the wall of said tube for engagement with the threads of the lens a 3. In a device of the class described, the combination with a lens having an externally threaded ferrule, of a mounting comprising-a support, an axially movable focusing tube slidably mounted on said support for receiving the lens ferrule, a plate having a stud extending through an aperture in the wall of said tube for engagement with the threads of the lens ferrule.

a cover detachably secured'to said support, a stem rotatably mounted on said cover, a knob on one end of said stem,.a cam on the other end of in operative engagement 7 with said plate for s I ting said tube axially upon said stem; positioned porting the latter mrelative axial sliding therein, a retractable stud extending through the wall of said tube for engagement with the ribbed outer surface of. the ferrule to permit the latter to be moved axially for rough focusing, and means for moving said stud axially of the assembly to accomplishilnefocusing.

5. In a device. of the class described, the combination with a lens having an e substantially circumferentially ribbed ferrule, of

a mounting having a supporting bore, a focusingtube axially slidable in said bore surrounding the ferrule and supporting the latter for relative axial sliding therein, said tube having aperture in its wall, a retractable stud closely.fitting said aperture and extending through it for engagement with the ferrule to exert a detent action on its ribbed surface permitting the ferrule to be moved axially in the tube for rough focusing, and means for moving said stud and focusing tube axially of complish fine focusing.

the assembly to move said tube and ferrule to ac- THOMAS J. MORGAN.

assurances crrnn The following references are of record in'the file of this patent:

UNITED STATES PA ENTS Number Name Date 1.780.945 Sapier Nov. 11, 1930 1,848,253 Howell Mar. 8, 1932- 1,855,775 Shapiro Apr. 26,- 1932 1,954,876 Joannides Apr. 17, 1934 2,116,704 Laube et al., .May 10, 1938 2,373,052 Rausch Apr. 3, 1945 Peck Sept. 10,1946- 

